Conventionally, an airtight and waterproof slide fastener is used for an opening and closing portion of a flexible container used for liquid transportation or an opening portion of special working clothes to ensure airtightness and waterproof property even under severe environments such as high pressure or high temperature and humidity. An example of such airtight and waterproof slide fastener is disclosed in, for example, JP UM 04-36657 B (Patent Document 1) and JP 2003-000309 A (Patent Document 2).
For example, the airtight and waterproof slide fastener 70 shown in Patent Document 1 comprises, as shown in FIG. 14, first and second fastener stringers 71a, 71b in which a plurality of fastener elements 73 are attached to facing tape side edge portions 72a of a pair of airtight and waterproof tapes 72, a backing tape piece 74 fixed so as to stride across the pair of airtight and waterproof tapes 72 at one end portion of the first and second fastener stringers 71a, 71b, a slider 75 slidably disposed along an element row comprised of the plurality of fastener elements 73, and a stopper (lower stopper) disposed at least at one end portion of the element row.
The airtight and waterproof tape 72a maintains its waterproof property by forming an airtight and waterproof layer on a tape front surface (first tape surface) of the fastener tape by rubberizing and such the fastener tape. The plurality of fastener elements 73 are attached to the tape side edge portion 72a of the airtight and waterproof tape 72, and each fastener element 73 has a spear-shaped coupling element comprising a coupling head portion at its forefront, and a clamp element with a U shape cross-section.
In this case, the tape side edge portion 72 of the airtight and waterproof tape 72 is bent in an Ω shape so as to embrace a base end portion of the coupling element in a state where the coupling head portion of the coupling element protrudes outwards. Further, the clamp element of the fastener element 73 is fixed on an outside of the Ω-shaped tape portion, the clamp element is swaged toward an inside, and the base end portion of the coupling element and the Ω-shaped tape portion are solidly sandwiched and fixed in the clamp element. By this, the fastener elements 73 are attached to the tape side edge portion 72a of the airtight and waterproof tape 72 with a required interval.
The backing tape piece 74 is adhered to a tape rear surface (second tape surface) side of the airtight and waterproof tape 72 of the first and second fastener stringers 71a, 71b.
The slider 75 of Patent Document 1 comprises a slider body 75a, a tab 75c holding protrusion 75b provided in a protruded manner in a tape width direction from a side surface of the slider body 75a, and a tab 75c held rotatably on the tab 75c holding protrusion 75b. A substantially Y-shaped guide hole which guides the fastener element 73 and the tape side edge portion 72a is provided inside the slider body 75a.
The stopper 76 is disposed on one end portion of the element row to prevent the slider 75 from dropping off from the element row. This stopper 76 comprises a block-shaped body portion 76a disposed so as to cover several fastener elements 73 and the bent tape side edge portion 72a, and a thin fin portion 76b disposed on an base end portion periphery (bottom end portion periphery) of the fastener tape side of the body portion 76a. And the stopper 76 is fixed at a bottom surface of the body portion 76a and the fin portion 76b so as to stride across the airtight and waterproof tape 72 and the backing tape piece 74, by injection molding.
Particularly, in the stopper 76 of Patent Document 1, a notch-shaped space portion 76c is formed on a bottom end portion of a contacting side surface to which the slider 75 of the body portion 76a contacts, and the fin portion 76b which is disposed on the slider 75 contacting side surface side of the body portion 76a is provided in a size to be accommodated inside the space portion 76c. That is, a forefront of the fin portion 76b disposed on the slider 75 contacting side surface side is positioned inward than the position of the slider 75 contacting side surface of the body portion 76a.
In the airtight and waterproof slide fastener 70 of Patent Document 1 comprising the above configuration, since the fin portion 76b of the slider 75 contacting side surface side of the stopper 76 is accommodated in the space portion 76c of the body portion 76a, even when the slider 75 strongly collides with the stopper 76, the slider 75 does not contact the fin portion 76b of the stopper 76. By this, when the slider 75 strongly collides with the stopper 76 repeatedly during a long period of use of the airtight and waterproof slide fastener 70, the fin portion 76b of the slider 75 contacting side surface side can be prevented from detaching due to collision of the slider 75.
On the other hand, in such airtight and waterproof slide fastener 70 of Patent Document 1, when for example it is bent or folded at a periphery portion of the stopper 76, it deforms so as to curve centering around a boundary portion of the body portion 76a and the fin portion 76b of the stopper 76, and can easily be bent. In this case, the fin portion 76b of the stopper 76 is bent at a sharp angle accompanying the curvature of the airtight and waterproof tape 72 and the backing tape piece 74, while a stress (force of restitution) to return to the original state between the body portion 76a directly acts on the fin portion 76b.
Because of this, when the airtight and waterproof slide fastener 70 is repeatedly bent or folded, there were cases where the fin portion 76b detaches from the bending airtight and waterproof tape 72 or the backing tape piece 74 due to action of the force of restitution, and it decreases or loses airtightness or waterproof property of the slide fastener.
With respect to the above problem of detaching of the fin portion, for example Patent Document 2 discloses an airtight and waterproof slide fastener in which a portion of a periphery portion of a fin portion disposed on a stopper comprises an extension which is adhered and fixed to an opening and closing end portion of a product to which a fastener is attached to which the airtight and waterproof slide fastener is attached.
To describe in detail referring to FIG. 15, the stopper 86 disposed on the airtight and waterproof slide fastener 80 of Patent Document 2 is fixed to stride across an airtight and waterproof tape 82 and a backing tape piece 84 by injection molding. And this stopper 86 comprises a substantially cubic-shape body portion 86a, and a fin portion 86b disposed on a lower end portion periphery of the body portion 86a. In this case, a thickness (dimension in a tape front and back direction) of the fin portion 86b is set to be 1.2 mm or more (the thickness of the fin portion 86b is set to 1.5 mm in the embodiment of Patent Document 2).
Also, the fin portion 86b is configured to have a size which extends outward than a position of an opening and closing end portion 88a of the product to which a fastener is attached 88 which is attached to the airtight and waterproof tape 82, shown by a two-dot chain line. By this, the fin portion 86b ensures a substantive fixing area with respect to the airtight and waterproof tape 82 or the backing tape piece 84, and increases the fixing strength of the stopper 86 (particularly the fin portion 86b).
Further, in Patent Document 2, by overlapping and adhesion integrating the opening and closing end portion 88a of the product to which a fastener is attached 88 on an upper surface of the fin portion 86b of the stopper 86 and an upper surface side of the airtight and waterproof tape 82, fixing of the fin portion 86b and the airtight and waterproof tape 82 is further strengthened.
In such airtight and waterproof slide fastener 80 of Patent Document 2, even when for example it is bent or folded at a periphery portion of the stopper 86, since the fin portion 86b is pressed from the upper surface side by the opening and closing end portion 88a of the product to which a fastener is attached 88 which overlaps on the fin portion 86b of the stopper 86, the fin portion 86b can be prevented from easily detaching from the airtight and waterproof tape 82 or the backing tape piece 84.